This invention is an inflatable stent which may be used within various portions of the body's vasculature.
In general, stents are prosthetic devices which may be introduced into a body cavity such as the lumen of a blood vessel or in some other difficultly accessible place. Stents are tubular bodies having a diameter which may be increased or decreased once they are properly positioned in the region where they are to be left. Stents are particularly useful for permanently widening a vessel which is either in a narrowed condition or has been damaged by aneurysm. Stents are typically introduced into the vasculature or other body cavity by the use of a catheter.
There are a variety of different stent designs. By far most of them are made of metal wire or ribbon. For instance, WO 92/02,246, owned by Numed, Inc., shows a radially expandable stent made from fine wire formed into a serpentine ribbon wound into a cylindrical shape for introduction into a body vessel. The stent is placed within the vessel over a balloon which, when expanded, expands the stent in a radial fashion to support the wall of the vessel in the expanded configuration. This stent is said to be useful in the transluminar implantation of a stent for use in coronary angioplasty to prevent restenosis.
Other disclosures of expandable intraluminal stents involving radially expanding wire mesh include U.S. Pat. No. 4,776,337, to Palmaz. The patent shows a tubular member which may be made of a variety of different things supported by a gridlike collection of metal or plastic wires. U.S. Pat. No. 4,800,882, to Gianturco, shows a wire stent made of a number of curved sections that are formed into a generally circular configuration.
None of these disclosures suggest a helically coiled inflatable stent such as is disclosed here.